How to Care for Japanese Kitchen Knives: Essential Guide for Maintenance and Sharpening

Japanese Knife Steel Basics

Japanese knives are made with harder steel than Western knives. The steel typically measures 60-67 HRC on the hardness scale, while Western knives usually measure 55-58 HRC. This harder steel holds a much sharper edge but can be damaged more easily if you use it incorrectly.

In addition, compared to Western knives, Japanese blades have thinner overall geometry combined with acute edge angles of 12-16 degrees per side compared to 20-22 degrees on Western knives. This combination gives you extremely sharp knives that cut with much less effort. However, the thin, hard steel needs careful handling to prevent chipping.

You'll find Japanese knives made with carbon steel or stainless steel. Carbon steel knives will rust if you don't maintain them properly.

How to Sharpen Japanese Knives

Whetstone Sharpening Guide

Whetstones are the best way to sharpen Japanese knives. They give you tactile feedback so you know exactly what's happening to the edge. Many knife enthusiasts find the sharpening process almost meditative - there's something zen-like about the focused, mindful work of restoring a blade's edge.

Choosing Stone Grit:

• 180-400 grit: for repairing chips or reprofiling damaged blades
• 800-1000 grit: for regular sharpening when your knife gets dull
• 3000-8000 grit: for polishing and final sharpening

Important Note: For double bevel knives like gyuto, santoku, bunka, nakiri, petty, and sujihiki, a #2000-#3000 stone is more than enough as your final finishing stone. You only want to go to higher grits like #8000 and above for single bevel knives like yanagiba.

Keys for Sharpening:

• Keep your angle consistent throughout the process
• Take your time - rushing leads to mistakes
• Master lower grits first. If you can't get sharp results at #1000, going to higher grits won't help
• Be mindful of your pressure. As you go to higher grits, use lighter pressure
• Use the "sharpie" trick to see where you are grinding or check your angle. Get a permanent marker and color the edge of your knife black. When you sharpen, the marker will be removed only where the stone touches the blade, showing you exactly where you're grinding

Sharpening Mistakes to Avoid

Never use electric sharpeners or pull-through sharpeners on Japanese knives. These tools will just damage your edges. Regular honing rods aren't recommended either. Ceramic rods can work, but if you're a beginner, we recommend skipping these rods altogether. Ceramic rods are fine if you're experienced and know what you're doing.

Best Cutting Boards for Japanese Knives

Cutting Board Materials

Your cutting board has a huge impact on how long your knife stays sharp. Hard surfaces will dull your knife quickly, while softer materials preserve the edge. This is especially important for Japanese knives since their harder steel, while holding a sharper edge longer, can also be more susceptible to damage from inappropriate cutting surfaces.

Construction Types

• End-grain cutting boards: create a "self-healing" effect as knife cuts separate wood fibers without cutting through them. Maintains its appearance longer since scratches are less visible due to the vertical grain orientation, but requires more upkeep and comes at a higher cost
• Edge-grain cutting boards: the most common type, providing a durable and practical cutting surface for everyday use. Simpler to care for and more budget-friendly due to easier manufacturing, but cutting marks become visible more quickly
• High-quality rubber boards: excellent for knife edges and the most practical choice since they're easy to maintain. No need for occasional oiling and sanding unlike wooden cutting boards

Recommended Wood Types

Japanese Woods:

• Hinoki (Japanese Cypress): Highly regarded for its gentle properties on knife edges. This lightweight wood is easy to maintain
• Ginkgo: Offers excellent value for knife care, favored by Japanese knife makers for its optimal balance of softness and durability

Western Wood Options:

• Black Cherry: An excellent choice for Japanese knives, offering the right softness to protect edges while maintaining good durability
• Maple (softer varieties): Provides reliable performance with enough give to preserve sharp edges while standing up to regular use

Materials to Avoid

• Bamboo boards: Inconsistent hardness and high silica content make these problematic for maintaining sharp edges
• Hard woods (Teak, Acacia, Hard Maple): Natural silica deposits in these woods accelerate edge dulling
• Glass, stone, or ceramic: These materials will immediately damage your knife's edge
• Hard plastic boards: The rigid surface gradually wears down knife edges with repeated use

Proper Japanese Knife Cutting Technique

Japanese knives work best with smooth, straight cuts. The ideal technique is push cutting - a forward and down motion rather than rocking the blade like you would with Western knives. While you can technically use rock chopping or guillotine-style cuts with certain Japanese knives, push cutting gives you the best results. Let the sharpness do the work with minimal pressure. Avoid twisting or applying side pressure, which can chip the blade.

Japanese Knife Cleaning and Storage

Daily Knife Care

Clean your knife right after you use it. Food residue and moisture can cause corrosion if left unattended, especially on carbon steel knives. Use water and mild dish soap with a soft sponge. Pay special attention to the area where the blade meets the handle to remove any food particles that get stuck there.

Japanese Knife Storage Options

Dry your knives completely after washing. Even stainless steel knives need proper drying to prevent water spots and potential corrosion. For carbon steel knives, this step is absolutely critical to prevent rust.

Good Storage Options:

• Magnetic knife strips: convenient access and holds knives securely
• Knife blocks with horizontal slots: protects edges well
• Individual blade guards: perfect for drawer storage
• Knife rolls: great for transport and when you have limited space

Avoid:

• Loose storage in drawers where knives can bang against other utensils
• Knife blocks with vertical slots that can damage blade edges
• Leaving knives in sinks or on wet surfaces

Japanese Knife Rust Prevention

How to Prevent Rust

For carbon steel knives, prevention is much easier than rust removal. Always dry your knives immediately after use. To build a good habit, make sure you wipe your knives dry regardless of whether they're stainless or carbon steel.

For long-term storage or transportation, apply a light coat of food-safe mineral oil. Oiling also helps if you live in a very humid environment (though in extremely humid climates, it's better to just get stainless steel knives instead). Store your knives in low-humidity areas when possible.

Important: There's a common misconception that you need to oil your knives every day. If you use your knives daily, there's no need to oil them every single day. Besides being a hassle for you, it's also completely unnecessary. Oiling is only needed for long-term storage, transportation, or very humid environments.

Understanding Patina vs Rust

Carbon steel knives naturally develop a patina over time. This darkening is completely normal and actually helps protect against rust. Once a stable patina forms, your knife becomes much easier to maintain since it's essentially protected.

Rust or Patina? The easiest way to check is by using tissue or a kitchen towel. Wipe the affected area. If there's color transfer, then it's rust. If there's none, then it's patina (your friend!).

For more detailed information about patina development and care, see our Japanese knife patina guide.

How to Remove Rust from Japanese Knives

For Light Rust:

1. Mix baking soda and lemon juice into a paste
2. Gently scrub the rust with the paste using a soft cloth
3. Rinse thoroughly and dry completely
4. Repeat the process if needed before moving to commercial products
5. For stubborn rust, use commercial products like Flitz

Japanese Knife Usage Guidelines

What Japanese Knives Are Best For

• Precise vegetable cutting and prep work
• Slicing fish and meat cleanly
• Fine mincing and dicing
• Clean cuts through soft to medium-firm ingredients

What to Avoid with Japanese Knives

• Cutting through bones or frozen foods
• Prying or twisting motions
• Opening cans or packages
• Cutting on hard surfaces outside the kitchen

Keep a Western-style knife or cleaver around for heavy-duty tasks like these. Japanese and Western knives make an excellent combination in the kitchen since they complement each other perfectly - use Japanese knives for precision work and Western knives for heavy-duty tasks. To learn more about the differences, check out our Japanese vs Western knife guide.

Common Japanese Knife Concerns Explained

Why My Japanese Knife Chipped

That harder steel and thinner geometry mentioned earlier comes with a trade-off - these knives, when used incorrectly, are more prone to chipping than their Western counterparts. It's like the difference between a razor blade and a butter knife - the razor is way sharper but needs gentler handling. But here's the thing: most chipping is actually user error rather than a flaw with the knife itself.

Most chipping happens from:

• Cutting on hard surfaces 
• Twisting or applying side pressure while cutting
• Hitting bones or frozen foods
• Storing knives where they can bang against other utensils

The good news? Once you get used to the proper cutting technique and care routine, chipping becomes pretty rare. These knives are designed to excel at precision cutting tasks, and when you use them for what they're meant to do, they'll perform beautifully for years.

Why My Japanese Knife Dulled So Quickly

If you sharpened your knife and it cuts well at first but suddenly loses sharpness literally after a few cuts, you most likely have an issue with proper deburring. This is the most common cause of knives that seem to dull quickly.

Deburr on every stone before moving up to the next grit. Use much lighter pressure and do alternating passes. Edge-leading strokes are recommended as this leads to a much cleaner edge and lower probability of forming a new burr.

Note that your cutting board also has an impact on edge retention. If you're still having issues after proper deburring, check your cutting board material, storage method, and cutting technique. Often, switching to a softer cutting board and improving your technique will make edges last much longer.

Why My Japanese Knife Got Rust Spots

Even stainless steel Japanese knives can develop rust spots if you're not careful with cleaning and drying. This usually happens when you leave moisture on the blade too long or store knives in humid conditions. For carbon steel knives, rust spots are much more likely if you skip the immediate drying step.

Most rust spots form from:

• Leaving knives wet or damp after washing
• Storing in humid environments without proper ventilation
• Leaving food residue on the blade too long
  

The fix is simple: stick to the cleaning routine we covered earlier. Clean immediately after use, dry completely, and store properly. If you already have light rust spots, the baking soda and lemon juice method we mentioned works well for removal.

Why My Japanese Knife Needs More Force to Cut

If you've sharpened your knives and they're sharp but don't go through food produce with ease like they used to, this is a sign that your knife needs some thinning. This is most obvious when you're cutting through dense vegetables like carrots. If it requires more force to cut compared to when it was new, then it's time to thin that knife.

Thinning literally means making the knife thinner. Thinning is required because as we sharpen our kitchen knives, the knife gradually becomes thicker as material is removed from the edge but not from the sides of the blade. Over time, this creates a wedge effect that makes cutting through food more difficult even when the edge is sharp.

You need a coarse stone to do this, but if it's your first time, we recommend asking a professional to do this for you.

Keeping Your Japanese Knife Sharp

How Often to Sharpen Japanese Knives

Sharpening frequency really depends on your specific situation. The obvious sign is when your knife struggles to cut through food. The most common example is with tomatoes - if your knife is sliding instead of cutting cleanly, then it's time to sharpen. But honestly, if it can't cut what you're trying to cut, then it's pretty obvious it needs sharpening.

Touching Up Your Knives

When you're touching up your knives, start with the highest grit possible. For gyuto knives, use #2000-#3000 stones. Keep the same angle as normal sharpening, but use lighter pressure and fewer passes. Think of it like honing a Western knife - it's just a quick tune-up to restore sharpness.

If your knife gets sharp again, you're done. If not, drop down to #1000 grit to do a proper sharpening.

About Stropping

While fancy leather strops and diamond sprays are nice to have, simple daily items like newspaper or denim work just fine for stropping. If you're a beginner, don't overthink stropping accessories for now. Focus first on mastering your medium grit stone. If you can't make your knives sharp with your medium stone, then these additional accessories won't help much.

Japanese Kitchen Knife Care Summary

Japanese kitchen knives need more care than Western knives, but proper maintenance keeps them performing at their absolute best. Use whetstones for sharpening your Japanese knives, choose appropriate cutting boards, clean and dry immediately after use, and store them properly.

These knives are precision tools designed for specific tasks. Use them correctly and maintain them regularly, and they'll provide excellent cutting performance for many years. The extra care required is definitely worth the superior results these Japanese kitchen knives deliver.